LITTLE DID WE KNOW that late August the most quoted publication in your friendly neighborhood tavern would be the New England Journal of Medicine. But by now, nearly everyone who enjoys an occasional belt has heard about a lead article in the Journal having to do with alcohol, coffee and heart disease. The suggestion is that a few drinks a day may actually help protect against heart disease. Given the play this study received in print and on the air, undoubtely there are more than a few vindicated tipplers jogging self-righteously to watering holes and package stores. But as a report by Washington Post staff writer Victor Cohn noted, there are medical experts who either dispute this finding or who cite other important reasons for not reading too much into it.

The conclusion in the Journal article was drawn from six year's study of heart disease of 7,705 men of Japanese descent in Hawaii. Dr. William Kannel, a leading authority on causes of heart disease, says in an accompanying editorial in the Journal that several other American and European studies have found similar evidence. Based on what doctors now know, he adds, "it is encouraging to note that not everything one enjoys in life predisposes to cardiovascular disease. There is nothing to suggest, for the present, that we must give up either coffee or alcohol in moderation to avoid a heart attack . . . I am sure that many who read this editorial will be quite willing to drink to that statement."

No doubt. But before the order another round, there are some sobering findings to take into account: For example, both Dr. Kannel and Dr. Abraham Kagan, who headed the study, caution that heavy drinking (which can be a sequel to "moderate" drinking) can severely harm the heart and other organs. Moreover, doctors at a medical center in California have found that three or more drinks a day increase the risk of developing high blood pressure, which increases the risk of heart disease and strokes.

So at the risk of being a wet - or should we say, dry? - blanket, Sen. William D. Hathaway (D-Maine), the chairman of the Senate subcommitte on alcoholism and drug abuse, issued a statement reminding people that "statistics show alcoholism to be our third most serious public health problem." That's not grounds for reviving Prohibition. But neither is it a statement you would want to drink heavily to.